Molecularly imprinted photoelectrochemical sensor based on Z-scheme SnIn4S8/CdS heterojunction for ultrasensitive detection of colchicine.

Herein, a Z-scheme SnIn4S8/CdS heterojunction with excellent photoelectric conversion efficiency as a photoelectric signal probe was prepared to construct a molecularly imprinted photoelectrochemical sensor (MIP-PECS) for ultrasensitive detection of colchicine (Col). The Z-scheme heterojunction exhibited remarkable photostability and photocurrent signals due to the synergistic optimization of broad-spectrum light absorption and high charge separation efficiency. Moreover, the molecularly imprinted polymer (MIP) film was formed by polymerization of the functional monomer m-phenylenediamine (m-PD), following by creating a tailored three-dimensional imprinted cavity with Col recognition sites. Consequently, the MIP-PECS achieved an ultrasensitive and specific detection of Col with a low detection limit of 1.22 nM and a wide linear range of 5.0 nM-0.25 mM, which is far superior to the reported works. The proposed sensor has been successfully applied to the detection of Col in human serum and urine samples, validating its reliability and potential application in complex biological matrices.